Child, Youth and Family says it is shocked by revelations a 2-year-old boy was disciplined by his previously "exemplary" caregivers with cold showers that caused life-threatening hypothermia.

An Eastern Bay of Plenty couple have admitted in court abusing the young boy over a five-week period. Eunice Towns, 42, pleaded guilty to grievous bodily harm and assault. Her husband, Stephen Towns, 52, pleaded guilty to assault.

Soon after the 2-year-old came into their care last year, the Edgecumbe couple began smacking him and giving him cold showers as a form of corrective discipline, the Whakatane District Court was told last week.

In one incident, the boy was under the cold water for between 10 and 15 minutes, and began suffering hypothermia within five minutes of getting out of the shower, the Whakatane Beacon reported.

He was unconscious when taken to Whakatane Hospital on May 11 and had a core body temperature of 31.6 degrees Celsius, placing him at risk of fatal cardiac dysrhythmia, the court was told.

Doctors also noticed multiple abrasions and extensive bruising over much of his body.

He appeared to have recovered well and was now being cared for by his wider family, CYF said last night.

The Towns couple became caregivers in July 2006 and had 24 children in their care over about six years, with a "previously exemplary record", CYF Midlands regional director Greg Versalko said.

"This couple had successfully cared for other children and there was no reason to believe this little boy would not be similarly looked after.

"We were as shocked as everyone else that these caregivers, who previously had an exemplary record, subjected this boy to such abuse. I am pleased they are being held to account for their actions."

The court was told that last year was a difficult one for the family, with stressful events affecting Eunice Towns' ability to react calmly to situations.

In spite of this, the couple agreed to take on the care of three children under the age of 3, including the boy, who arrived in early April.

Within three weeks the couple were feeling the stress and began using excessive force when grabbing the toddler, bruising various parts of his body.

As discipline, Eunice Towns began giving the boy regular cold showers of up to a minute, up to three times a day.

Her husband would use similar disciplinary action.

On May 11, when the boy refused first to eat his breakfast, then play with his toys, Eunice Towns took him to the shower, where she made him sit under the fully cold water for five minutes before increasing the temperature to wash him.

Another woman took over the showering and noticed the temperature but made no attempt to increase it.

This was the incident in which the boy became hypothermic.

The Towns couple will be sentenced in the Tauranga District Court on February 18.

The second woman, aged 19, faces a charge of wounding with reckless disregard, to which she has pleaded not guilty. She has interim name suppression and will next appear in the Whakatane court on February 5.

The court was told Eunice Towns had expressed extreme remorse but could not provide an explanation for what she had done.

CYF said that as soon as the abuse became known, it removed the children the couple were caring for and revoked their caregiver status.

"This little boy is being cared for by his wider family and appears to have recovered well."